1. Field of the Invention
The present invention relates to an electric junction box for a vehicle, and more particularly, to an electric junction box in which a connector is inserted and latched through an aperture provided in a main case.
2. Description of Related Art
A conventional electric junction box for a vehicle includes a retainer for double latching terminals attached to a connector that is fitted into a connector receptacle of the electric junction box. For example, in an electric junction box disclosed in Japanese Patent Laid-Open Publication 2002-291137, as shown in FIG. 8A, a terminal receptacle 2 aligning numerous terminal chambers 2a is provided on an upper surface of an upper case 1. A retainer insertion slot 2b is provided at a side of the terminal receptacle 2 to receive insertion of a retainer 3 having a comb-like shape. The retainer 3 has insertion plates 3b aligned and projecting in parallel from a press plate 3a, and the insertion plates 3b are inserted into the terminal chambers 2a. Each insertion plate 3b has two latch projections 3c. As shown in FIG. 8B, each latch projection 3c latches a respective indentation 4a of a terminal 4 inserted into the terminal chamber 2a. Accordingly, through the use of the retainer 3 for double latching the terminals, it is possible to detect partial insertion of the terminals 4 inserted into the terminal chambers 2a, thereby improving the electrical connectivity between the external wires and internal circuit.
However, in Japanese Patent Laid-Open Publication H2-285906, as shown in FIG. 9, which discloses a through connector 6 fitted and latched with an aperture 5 of a case, it is preferable that terminals of the wire terminals inserted into the through connector 6 are double latched, since the terminals in the through connector 6 are pressed with a load when a mating connector 7 is fitted from above. However, the JP H2-285906 device does not provide the double latch mechanism for the terminals in the through connector 6. This is because a retainer cannot be easily attached to the through connector 6 to be fitted with the aperture 5 of the case, since the outer perimeter of the connector is surrounded by an internal perimeter surface of the aperture 5.
In other words, when the retainer for the double latch is to be attached to the through connector 6, as shown in FIGS. 10A and 10B, the through connector 6 is moved downward and assembled into the aperture 5. Thus, wires W need to be inserted through the aperture 5 so as to insert and latch terminals t, which are connected to the upper ends of the wires, with the through connector 6 in an upper location. Therefore, an excess length of wires is created, which is longer than the length of wires required when the through connector 6 is attached to a normal position within the aperture 5. Further, after the retainer 8, which double latches the terminals t inserted and latched within the through connector 6, is attached to the aperture 5, the retainer insertion slot is surrounded by the internal surface of the aperture 5, thereby preventing the insertion of the retainer. Therefore, the retainer 8 is inserted into and latched with the through connector 6, and while retaining the double latch state, the through connector 6 is attached within the aperture 5. Thus, when there is erroneous connection of terminals in the through connector 6 attached within the aperture 5, it is impossible to remove the retainer to correct the erroneous connection.